One of the more interesting recent comebacks is Al Gore's reinvention as a campaigner for the environment. As a Senator and Vice President, Gore was always a fervent advocate for the environment, but other political issues competed for his attention. Now, he can focus full time on an issue he feels strongly about. An Inconvenient Truth mixes Gore's multimedia presentation on global warming with some extended interviews with the man himself. The immediate takeaway is that Gore finally sounds a lot less stiff than he did when campaigning for President. And part of the movie plays like a potential campaign.

An Inconvenient Truth works because director Davis Guggenheim (Gossip) gives Gore the time to give a detailed, coherent argument. It also helps that Gore has this nailed down flat. In the film, he claims to have given the speech over one thousand times, all across the world. Gore asserts that it is scientific fact that the Earth is getting warmer. Using reams and reams of data, he says that humans are the reason for the warming. The hottest years on record are all in the recent past. And unlike his earlier campaign persona, Gore is passionate and easy to understand. An Inconvenient Truth is at its strongest when he shows the effects of global warming. The Antarctic ice shelf melts and breaks off in an impossibly quick amount of time. Photographs of glaciers today compared with those from a few decades ago are vastly different. Seasons are changing. Hurricanes are getting worse, and non-native species are invading.

Gore resists the urge to turn political for most of the movie. The sheer amount of information is enough to provide a convincing argument. He moves quickly and logically between subjects, showing how warmer climates affect all sorts of things. The movie ends on a strong note. Now that Gore shows what is wrong, he and Guggenheim show what people can do. This shows that they really care about what they're speaking about. But before this happens, Gore yields to temptation and begins bashing (albeit mildly) the Bush administration. Although some of it is well deserved, most of it sounds a bit too much like sour grapes, and casts a negative slant on his carefully constructed argument. The only other weakness in An Inconvenient Truth is a pretty big one. Why watch a movie of a guy giving a multimedia presentation? Parts of the film are basically Gore in front of an audience with a screen behind him. This isn't very interesting, and most documentaries know this. When Guggenheim removes the setting and focuses on the pictures, or shows brief clips of Gore around the world, the movie has a sense of energy. It all gets sucked away when they move back to Gore giving a speech. The message may be strong, but the medium needs to help, not hinder it.